Mine door latch



Jan. 17, 1961 D. F. MONTGQMERY 8,50

I MINE DOOR LATCH 2 Sheets-Sheet 1 Filed March 31, 1959 a M Jj I P H-kl IM.

/2 TI'FITITIF F] H W IN VEN TOR.

9 BY 1... m

Dennis E Montgomery JaJ1- 1961 D. F. MONTGOMERY ,968,507

MINE DOOR LATCH Filed March 31. 1959 2 Sheets-Sheet 2 5b Den/111s E Montgomery INVENTOR.

United States atent Patented Jan. 17, 1951 2,968,507 MINE DOOR LATCH Dennis F. Montgomery, P.0. Box 135, Divernon, Ill.

Filed Mar. 31, 1959, Ser. No. 803,278 7 Claims. (Cl. 292-446) This invention relates in general to new and useful improvements in latch constructions, and more particularly to a latch for a mine door.

There are doors in mines all over the country that seal otf passages in the mines and are automatically opened. These doors are opened by a trip rail that a mine locomotive runs over just before passing through the doors. The weight of the locomotive and cars press the trip rail down and the doors open more or less violently. When the doors are fully opened, they hit what is commonly referred to as a slam post. The violence of the impact upon striking the slam post causes the doors to rebound excessively, sometimes so much that the locomotive strikes a partially open door and demolishes the door. Further, during this door demolishing accident, many times the man operating the locomotive is injured. This, of course, is an undesirable situation.

It is therefore the primary object of this invention to provide a latch for mine dOOrs which will automatically latch the mine door to a slam post upon striking the slam post, the latch being of such a nature that it only retains the door in an open position for a short time, after which it releases the door to return to its normal position transversely of the tunnel or passage in which it is mounted.

Another object of the invention is to provide a latch for a mine door, the latch including a latch bar which is mounted on the slam post for the mine door, and a yoke which is mounted directly on the door, the yoke being pivotally connected to the door and being swung relative to the door and into engagement with the latch bar upon the door striking the slam post and suddenly stopping.

Still another object of the invention is to provide an improved latch for a door, such as a mine door, wherein the latch will momentarily hold the door in an open position, the latch including a latch bar which is mounted on the slam post for the door, and a yoke which is pivotally mounted on a door and engageable behind the latch bar, the yoke being mounted on a sloping hinge pin whereby it is constantly urged to a lowermost position, which position is in alignment with the mine door so as to bring about the releasing of the yoke from the latch bar.

A further object of the invention is to provide a cooperating latch assembly to be used on a mine door with a portion of the latch assembly being mounted on the mine door and the remainderthereof being mounted on the slam post for the mine door, the latch assembly including a pivotally mounted yoke which is constantly urged towards a position aligned with the mine door but is swingable to a position generally at right angles to the mine door upon the striking of a slam post by .the mine door, and the yoke being engageable with a latch bar on the slam post for temporarily holding the door in its open position.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a fragmentary plan view taken through a tunnel and shows the mine door and its latch, only one door of a pair of doors being fully shown, the other door of the pair of doors being shown in dash lines, and the one door being shown in its open position by dotted lines;

Figure 2 is an enlarged end view looking into the end of the mine door when in its open position and just about ready to engage the slam post, the latching position of the yoke of the latch being shown by dotted lines;

Figure 3 is an enlarged fragmentary vertical sectional View taken substantially upon a line indicated by section line 3-3 of Figure 2 and shows the specific details of the construction of that part of the latch carried by the mine door; and

Figure 4 is a transverse sectional view taken substantially upon the plane indicated by the section line 4*4 of Figure 3 and show-s further the details of the latch, the relationship between the yoke of the latch and the latch bar being shown by dotted lines.

Reference is now had to Figure 1 of the drawings wherein there is illustrated a mining tunnel or passage generally referred to by the numeral 10. A railway track 12 extends through the tunnel 10 and the tunnel 10 is sealed by a pair of mine doors 14 which have their inner ends in overlapping relation. Since the two mine doors 14 are identical, the invention will be described with respect to onlyone of these doors.

The mine door 14 is vertically disposed and is mounted on a supporting post 16 by a hinge 18. The hinge 18 preferably will be of the spring loaded type which will effect the automatic closing of the mine door 14. A trip mechanism (not shown) operated by a locomotive moving along the track 12, will swing the mine door 14 to a fully open position and cause it to engage a stop which is called a slam post 20. It is desired that the mine door 14 be held in its fully open position, as shown by dotted lines in Figure l, momentarily so as to permit the locomotive and the cars attached thereto to pass without striking the mine door. In order to accomplish this, there has been provided the latch assembly which is the subject of this invention, the latch assembly being generally referred to by the numeral 22.

The latch assembly 22 includes a panel-shaped mounting bracket 24 which is adjustably secured on the free end of the mine door 14. A pair of straps 26 and 28, which are vertically spaced, extend endwise from the mounting bracket 24 and support a pair of aligned sleeves 30 and 32, respectively. It is to be noted that the axis of the sleeves 30 and 32 slope downwardly and towards the end of the door 14. A hinge pin 34 is seated in the sleeves 30 and 32 and is retained in place by a pin 36 passing through the upper end of the hinge pin 34.

A latch yoke generally referred to by the numeral 38 is pivotally mounted on the hinge pin 34. The latch yoke 33 includes a sleeve 40 which has roller bearings 42 mounted in opposite ends thereof, which roller bearings engage the hinge pin 34. The opposite ends of the sleeve 46 are closed by cover plates 44 which engage the sleeves 30 and 32. A pair of arms 46 extend out from the sleeve 40 adjacent the opposite end thereof. The outer ends of the arms 46 are connected together by a cylindrical latch pin 48 which is disposed generally parallel to the hinge pin 34.

It is to be noted that the yoke 38 slopes downwardly and away from the mine door 14 due to the angle at which the hinge pin 34 is mounted. As the yoke 38 swings about the hinge pin 34, it will swing uphill with the result that when released, the yoke 38 will swing back to its original position aligned with the door 14, as is best shown in Figure 4. Swinging of the yoke 38 in a counter-clockwise direction is limited by a stop member 50 which is secured to the sleeve 40 and which abuts the mounting bracket 24- when the yoke 38 is aligned with the door 14.

The latch assembly 22 also includes a mounting plate 52 which is adjustably secured on the slampost 20 in the position best illustrated in Figure l. The mounting plate 52 is held in place on the slam post 20 by a pair of fasteners 54 which pass through the elongated slot 56 in the mounting plate 52. A generally horizontally disposed latch bar 58 projects outwardly from the mounting plate 52. The latch bar 58 has a rearwardly sloping front face portion 60 which may be engaged by the latch pin 48 to facilitate themovement of the latch pin 48 around to the back of the latch bar 58 and into latching engagement.

Operation In the operation of the latch assembly 22, the mine door 14 is violently swung to its open position when the locomotive contacts the trip mechanism with the result that it strikes the slam post 20 and suddenly stops. The inertia of the latch yoke 38 results in the latch yoke swinging about the hinge pin 34 and the engagement of the latch pin 48 behind the latch bar 50, as is shown by dotted lines in Figures 2 and 4. Thus, the mine door 14 is temporarily latched to the slam post 20 and rebounding of the mine door 14 into the path of a locomotive or cars of a train is prevented. The normal rebound maintains the latch pin 48 in engagement with the latch bar 58 but after a short period of time the rebounding force of the mine door 14 will be diminished to the point that the gravitational force on the yoke 38 will be sufi'icient to swing the yoke 38 out of engagement with the latch bar 58 with the result that the mine door 14 will be free to close after the last of the cars have passed therebeyond. Although the door is spring urged closed, the spring urging is insuificient to cause such an engagement of the latch pin 48 and latch bar 58 as would prevent the gravitational movement of the yoke 38 and disengagement of pin 48 and bar 58. It is to be understood that the mine door 14 is held in its opened position by the continuous engagement of the trip mechanism for the mine door 14 by the cars passing along the track 12. The latch assembly 22 retains the door 14 open for a slight period after disengagement of the trip mechanism.

At this time it is pointed out that by making the latch pin 48 cylindrical and by tapering the front edge of the latch bar '58, such as at 60, the engagement of the latch pin 48 behind the latch bar 58 is greatly facilitated. From the foregoing, the construction and operation of the device will be readily understood and further eX- planation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A.mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, said hinge pin sloping downwardly and towards said mine door, and a latch yoke pivotally mounted on said hinge pin, the slope of said hinge pin urging said latch yoke to a position aligned with said mine door.

2. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, said hinge pin sloping downwardly and towards said mine door,- and a latch yoke pivotally mounted on said hinge pin,jthe slope of said hinge pin urging said latch yoke to a position aligned with said mine door, said latch yoke including a cylindrical latch pin to facilitate sliding of saidlatch pin over said latch bar.

3. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, said hinge pin sloping downwardly and towards said mine door, and a latch yokepivotally mounted on said hinge pin, the slope of said hinge pin urging said latch yoke to a position aligned withsaid mine door, said latch yoke including a cylindrical latch pin to facilitate sliding of said latch pin over said latch bar, said latch bar having a sloping front face to facilitate sliding movement of said latch pin around said latch bar.

4. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door'and said slam post for temporarily retaining said inine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, said hinge pin sloping downwardly and towards said mine door, and a latch yoke pivotally mounted on said hinge pin, the slope of said hinge pin urging said latch yoke to a position aligned with said mine door, said latch yoke including a sleeve telescoped over said hinge pin, bearings in said sleeve engaging said hinge pin.

5. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, a latch yoke pivotally mounted on said hinge pin and biased to a normal position in alignment with said mine door.

6. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, a latch yoke pivotally mounted on said hinge pin and biased to a normal position in alignment with said mine door, said latch yoke including a cylin-.

drical latch pin to facilitate sliding of said latch pin over said latch bar.

7. A mine door assembly comprising a mine door, a slam post for limiting the opening movement of said mine door, and cooperating latch means on said mine door and said slam post for temporarily retaining said mine door adjacent said slam post, said latch means including a latch bar on said slam post, a hinge pin mounted at a free end of said mine door, a latch yoke pivotally mounted on said hinge pin and biased to a normal position in alignment with said mine door, said latch yoke including a cylindrical latch pin to facilitate sliding of said latch pin over said latch bar, said latch bar having a sloping front face to facilitate sliding movement of said latch pin around said latch bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,888,869 Spangenberg Nov. 22, 1932 2,783,071 Williams Feb. 26, 1957 FOREIGN PATENTS 1,093,879 France Nov. 24, 1954 

